Electrical control system for operating railway track switches, draw spans, turntables, and the like



H. R. STEVENS, R. L. ROCKWELL, AND E. G. HOWE. ELECTRICAL CONTROL SYSTEM FOR OPERATING RAILWAY TRACK SWITCHES, DRAW SPANS,

TURN TABLES, AND THE LIKE- aPPUc/mdu msb was 12, ms.

Patented Mar. 28, 192 2.

2 $HEETS-SHEET I;

lNVEN-TORS I H. R. STEVENS, R. L ROCKWELL, AND E. e. HOWE. ELECTRICAL CONTROL SYSTEM FOR OPERATING RAILWAY TRACK SWHCHES, DRAW SPANS,

TURNTABLES, AND THE LIKE.

v 7 APPLICATION FILED JUNE 12. 1918. r

1,410,844, I Patented Mar. 28, 1922 2 SHEETS-SHEET 2- INVENTORS hen/(y. 2? 6262/6218, fibaE/PT' L. Roe/{WELL Zwzesi' G. Hon e.

ATTORNEY STA ES PATENT HENRY n. STEVENS, ROBERT L. nocxwnnn, AND ERNEST e. isown, or SEATTLE, WASHINGTON, assrenons, 'BY MnsNE ASSIGNMENTS, To ROYAL A. MCCLURE,

'JEssn 1v. BLALOCK, ALBERT E. HoLLANn'nAv-in O. MGCLAY, ERNEST G.

HOWE, ALL or SEATTLE, WASHINGTON, TRUSTEES.

ELECTRICAL CONTROL YS'IEM FOR OPERATINGRAILWAY TRACK SWITCHES, DRAW SPANS,TURN'JUABLES, AND THE LIKE.

i lt'l (7 ,844

To; all whom it may concern:

Be it known that we, HENRY R. :Srnvnns, ROBERT L. Roonwnnn, and ERNEST G. HOWE, citizens of the United States, residing at Seattle, in the county of King and State of lVashington, have invented a new and useful Improvement in Electrical Control Systems tor Operating Railway; Track Switches, Draw Spans, Turntables, and the like, of which the following is a specification.

This invention relates to improvements in electrical control systems for operating railway track switches, draw spans turn tables and the like, and the object of this improvement is to provide a reliable and eflicient electrical control system which may be set in operation by the closing otanelectric circuit and which will, then operate automatically to unlock, move and lock any desired piece-oi? mechanism, as for instance a switch, turntable or draw span;

The invention is herein shown as applied to a monorail track switch, a monorail turntable and a ,cantalever bridge span of. a form more thoroughly disclosed in United States Patents No. 1,286,042 covering improvements in railway track switches, issued to Universal Elevated Railway Company Nov. 26, 1918, and No. 1,326,362, covering improvements in, turntables, issued to Universal Elevated Railway Company April (1, 1920, but it will be understood that this control system is equally well adapted for use with various other forms of mechanism where the same or a similar series of operations are to be performed. i

In the accompanying drawings, Figure 1 is a wiring diagram illustrating theinvention, and .l igs. 2, 3 and 4 are diagrammatic views illustrating one manner of applying the invention to a switch, a turntable. and a cantalever bridge respectively. Fig. 5 is a sectional side elevation of the latch niotor limit switch showing the method of actuating the switch by means of a rod connected to the movable section lock bolt. Fig. ('3 is an enlarged fragmentary plan view of the limit switch to more clearly show the method oi? mounting and actuating the Specification of Letters Patent. Patented NIaI. 28, 1922- Application filed June 12, 1918. Serial 110,239,677.

ratchet wheel element, and its relation to the switch members and ball race casting This control system, when applied to a track switch, turntable or bridge span, the sequence of operation at the closing switch is as follows: The first operation unlocks a movable track section from an initial position; the second operation swings themovable track section to anew position; the third operation locks the track section in the new position; the closing of another switch starts a series of operations that un lock the movable section, swingsit back to the initial position and locks it in the initial position.

Referring to the drawings, throughout which like reference numerals indicate like parts, the numerals land 1 Fig. 2, indicate the main rails of a single rail tack, and 2 indicates a turnout or siding rail that branches off from the main track.

3 and A; indicate two switch rail sections that are secured to each other and pivoted, as at, 5, so that they will be moved from the position shown by full lines to the position shown by broken lines to selectively es tablish connection between the two ma-in line rail sections 1 and l or between the main rail section 1 and the sidingrail sec tion 2.

The purpose of this invention is to provide an automatic electric control system that will enable the motorman as he approaches the track switch to close an electrical contact andsetin motion machinery that will unlock the switch members 3 and- 4, swing them to a new them in the new position.

Fig. 2 illustrates the same system as ap plied to atnrntable 6 that may be inter posed in the track line between two main linerail sections '7 and 7" and two cross line rail sections 8 and S and operated by the closing ofa switch to unlock the turntable, swing it through an angle of 90 and lock it in the new position.

Fig. 4 illustrates the same system as applied to a cantalever span 9 that may be interposed between two rail sections 10 andlO.

Throughout the following description it position and lock it is desired to move such switch members into the position shown by broken lines to permit a car 11 to passto the siding track 2 and then to move the switch members back 7 into the position shown by full lines.

The car 11 is provided with the usual trolley-pole 12 that is connected by wires 13 and 14 and switch 15 with a contact shoe 16 that is adapted to'make contact with an insulated rail section 17 located near the track 1 at a short distance from the switch sections 3 and 4. Y

'As the car 11 approaches the switch, the operator will bring such car to a stop-with the shoe 16 in contact with theinsulated rail section and to throw the track switch formed by the rail sect-ions 3 and 4 he would close the electric switch 15 which may be so arranged that it is mechanically interlocked with the controller forthe car, drawing motors and the main air valve so that it is impossible to close such switch unless the current to the driving motors is turned off and the brake set, thus insuring a'complete stopping of the car before the switch is closed.

Upon closing the switch15, current will flow from the trolley wire 18, Fig. 1, through trolley pole 12, connecting wire 13, switch 15,

connecting wire 14, contact shoe 16, insulated rail section 17, wire 19, current limited resistance 20, relay solenoids 21 and 22 connected in parallel, wire 23 to terminal 38, thence through wire 25 and solenoid 26to wire 27, which is permanently connectedto track section 1 and back to the source of: supply. (Call this circuit 1.)

This flow of current energizes solenoids 21 and 22 which raise the iron plungers 21 and 22 respectively, closing contacts 28 and 29. The closing of these contacts completes two other circuits, one of which, circuit 2, is from positive terminal 30, through wires 31, 32 and 33, contact 28, wire 34, switch blade 35 of'limit switch 36, blade 37, wire 24, solenoids 21 and'22, and wire 23 to negative terminal 38, thus holding closed the contacts 28 and 29 after the current has once been sent through them by closing the switch 15. The other circuit referred to, and herein designated as circuit 3, is from the positive terminal 30, through wires 31, 32 and contact 28, wire 34, blades35, wire 39, field magnet winding 40, and arn'iature 41 of the latch operating motor, which is of comparatively small size, then through switch blade 42, wire 43, contacts 29 and wire 23 to the negative terminal 38.

This current thus flows through the'circuit and drives the latch operating motor in such a direction as to throw a bolt 41', unlock the switch whichrequires a predetermined definite number of revolutions of the motor. At the end of the number of revolutions the limit switch, 36 is thrown to the right, by

. means of rods 41" attached to lock bolt 41.

A quick break at contacts 44 and quick connection with contacts 45 is insured bymeans ofball race casting 13 and ball 13 mount-- ed separate from the switch blades 35, 37 and 42, on switch base 12. In unlocking the track section, rod 41" carrying pin 41" engages the forked projection 13 and carries the ball race casting to the right until its radial center line passes. the vertical center line of the limit switch. Ball 13" then rolls to the other end of the ball race of casting 13 which engages the elevated ends of the bent switch blades 35, 37 and 42 and drives them into contact jaws 45. It is evident that when the switch blades 42, 37 and 35 leave contacts 44, both circuit 2 and circuit 3 are opened which allows plungers 21 and 22 to fall, thus breaking the circuits at contacts 28 and 29, which in turn also. opens the circuits 2 and3, as both include contacts 28. It is also evident that these circuits are not again completed when the switch blades 42, 37 and 35 close the contacts 45.

Referring to Figs. 5 and 6 in addition to Fig. 1, contact finger 46 is mounted on a projection 13" cast integral with the ball race casting 13 which has suit-able journals (not shown) straddling switch blade 37 and carried in bearings (not shown) mounted on base 12 of suitable insulating material. This construction permits the ball race casting 13' together with contact finger 46 to be rotated through an angle of 90 degrees about the center of ratchet wheel 48 against which contact finger 46 is held by spring 49 also secured to ball race casting 13. ires 32 and 33 of Fig. 1 connect to the bearings (not shown) supporting ball race casting 13 which in turn makes connection with contact finger 46.- Insulation sections 47, 47 47" and 47 are placed in slots in metallic ratchet wheel 48 which is supported by the spindle projection 50 made integral with pedestal casting 50 which'in turn is secured to'switch base 12' by means of screws 17 The ratchet projections of pedestal casting 50 meshing with similar projections from the hub 48 prevent the rotation of ratchet wheel 48 in'a clockwise direction, but by compressing spring 49 against washer 16 held in place by nut 15 it is allowed to rotate in a counter clockwise direction.

When ball race casting is thrown to the right by the movement of rod 48" in the direction of the arrow, Fig. 5, and the switch blades 35, '37 and 42 make contact with j aws 45, contact finger 46 is drawn in a clockwise direction from insulation section 47 to insulation section 47, the ratchet wheel remaining stationary. During the movement of the contact finger an electrical contact is made between finger '46 and ratchet wheel 48, which closes another circuit which 'we'call circuit 4 that starts the track switch motor 51,

iVith finger 46 .in contact with; ratchet wheel 48, current flows from the, positive terminal 30, through wires 31 andv 32, finger 46, ratchet 48, wire 52, current limiting resistance 53, contactorimagnet coil 54, wire 65, contacts 117 ,wire 55, contact fingers 56, contact segments 57 on track motor limit switch 36 to contact finger 58, thence through wire 59 to the negative terminal 38.

Magnet coil 54 closes contactors 60 and 61 which operate together because of the mechanical connection through a bar of electricalinsulating material 62. The closing of these contactors completes another circuit through magnet 'coil 54, which will be referred to as circuit 5 and which isas follows:

' From the positive terminal 63,through wire 64, magnet coil '54, wire 65, contacts 117, wire 55', contact finger 56, contact segment 57, contact finger 58, and wire59 to negative terminal 38, thus keepingjthe contactors 60 and 61' closed after being once closed by current flow through circuit 4. Amechanical brake is providedwhich is attached to the shaft of the track switch m0- tor, being kept normally in the operative condition by means of heavy springs, an electromagnet, usually of theironclad plunger type, is so connected mechanically to the brake mechanism that when the magnet is energized the resultant movement of the plunger 'releasesthe brake and allows the motor to turn freely. The brake sets again as soon as current ceases to flow through the releasing magnet.

Whenever contactors 60 and 61 are closed,

current flows from terminal 63 through wires 68 and 80,'brake magnet coil 81, wires 82, to negative terminal 83, thus releasing the brake. r 1

A circuit hereinafter referred to as circuit 6 is formed by the closing of contactors '60 and-61* which energizes also two of the motor magnets 66 and 67 by means of the circuit from the positive terminal 63, through wire 68, contact finger69, contact segment 70, contact finger 71and-wire 72 to' a point 73 where the circuit dividesbetween points 73 and 7 4 as follows: The first branch from the point 73 passesthrough wire 7 5, into lock contact-76, wire 77 and magnet coil 67,which closes contactor 78 to point 74. a

The secondbranch passes from the point armature reversing contactor 73-, through wire 79, into lock contactors 84, wire 85, magnet 66, which closes contactor 86 and wires 87 and 88 to point 74. From the point 74 the circuit is through wires 89, 90and 91, to negative terminal 83.

With contactors 60, 61, 86 and 78 closed, the track switch motor will rotatein the proper direction to throw the track switch, the flow of current being from the source of supply, through trolley wire 18, which is tapped by wire, 92, through solenoid 93, wire 94, contactor 60, wires and 96, solenoid 97, wire 98, solenoid 99, wire 100, solenoid 101, wire 102, gridresister sections 103, 104, and 106, wires 107 and 108, contactor 86, wire 109, interpole winding 110, and armature 51, of the track switch motor; thence through wire 111, contactor 78, wires 112 and 113,series field winding 114, wire 115, contactor 61, wire 25, solenoid 26 and wire 27, which connects with the track through which the current flows back to the source of supply, thereby forming a circuit hereinafterreferred to as circuit 7 f It is evident that circuit 7 includes all of the grid resister sections when current is first turned into the motor. As the armature speed increases, it is necessary to cut out these sections one at a time,iat the same time keeping the current in the circuit within a prescribed limit. This is accomplished by means of contactors 118, 119, and 121, which close in the order named. The operation of the central circuit will be better understood by noting that ,7

1st. Contactors60, 118, 119 and 120 hold their respective plungers 122, 123, 124 and 125 in raised positions so that contacts 126,

.127, 128 and 129 respectively are broken.

The weight of the plungers and the design of the solenoids are such that if the motor current exceeds the predetermined value previously mentioned the solenoids will hold the plungers away from the contacts, it the plunger is in that position when the current isturned on, but the strength of the solenoids is not sufficient to raise the plungers after they have dropped down, due to the decrease in current value, even if the'current be increased *again'to its initial value.

2nd. The contactors referred to, by means of the projections 130, 131, 132 and 133 respectively hold up their respective plungers within the solenoids as long as thecontactors areopeiLbut-upon closing any one of the cont actors the respective plunger is prevented from falling only by the attractive action ot-the solenoid energized by the motor circuit current.

3rd. The disk interlocks 134, 135, 186 and 137 aremechanically operated by contactors 86, 138, 78 and 139, respectively by means of their respective projections 140, 141, 142 and. 143. In each case the top set of disk contacts are closed when the designated as circuit 8.

From positlve terminal 63, through wire 68, contact finger 69, wire 144 and 145, contact 146, wire 147, contacts 148, wires 149, 150 and151, contacts 126, wire 152, contactor magnet coil 153, wires 154, 155, 156 and 91, to negative terminal 83. This includes onlythe first branch. I Magnet coil 153 closes contactor 118, which it vwill be noted short circuits wire 102 and grid resister 103 out of circuit 7*,

thus increasing the flow of current in the circuit-again SOtllELtSOl6I101CllO1 prevents the closing of'contacts 127 until the current again decreases to the prescribed limit.

The/first branch of circuit 8 consists of wire 151, contacts 126, wire 152, and.mag net coil 153.

As the armature 51 gains more speed and the current through the solenoid 101 decreases, plunger 123 drops, closing contacts 127, which allow current to flow through the second branch of circuit 8, consisting 0 contacts 127, wire 157, and magnet coil 158,

V whichcloses contactor 119, which short cirp 100, 101, 102, 103, 104, 105, and 106 of cir cuit 7 thus connecting the motor directly cuits sections 100, 101, 102, 103 and 104 from circuit 7 and again brings current, above the prescribed limit. When the current again decreases, it allows plunger 124 to drop, thus completing the third branch of circuit 8, which comprises contacts 128, wire 159 and magnet coil 160. This closes contactor 120, which short circuits sections 98, 99, 100, 101, 102, 103, 104 and 105 ofcircuit 7 Band again brings the current in that cir cuit above the prescribed limit.

Then the speed of thearmature comes up toits rated value, and the current again decreases, thereby allowing plunger 125 to fall, the fourth branch of circuit 8 is completed.

This consists. of contacts 129, wire 161 and.

magnet coil 162, which closes contactor 121, which short circuits sections 96, 97 ,98, 99,

across the terminals 63 and 83 and applying full line voltage,

After the motor has completed sufiicient revolutions to swing the curved switch section 4, Fig. 2, so as to engage the main track section 1, the limit switch is thrown quickly so contact segments 163 and 164 make contact-with contact fingers 58, 56, 69

and 165. Contact segments 57, 70 and 166 would then appear to the right of the row of contact fingers in the diagram of Fig. 1.

This movement of the limit switch opens control circuits 5, 6 and 8, which allow all previously closed contactors to open motor circuit 7 A and in addition opens the motor brake solenoid circuit, allowing the brake to bring the motor to a quick stop. Q It will be noted that these circuits are not closed completely again when'the new set of connections are made between the contact segments andfingers of thelimit switch; but again require the closing of contactors and 61, which in turn requires the closing of circuit 4 through the contact fingers 46 and ratchetwheel' 48, hence requires operation of the latch motorv in the direction for opening the latch before the track switch motor can again be operated. I

It will benoticed that when the track switch motoractuates the limit switch in either. direction, a momentary contact will be made between, the contact fingers 167, 168,]and contact segments 1.66.. This coma pletes circuit 9 from terminal 30 through wlres tact segment 166,.contact finger 168 and wire 170, current limiting resistance 171,. sole: noids 21 and 22 in parallel, wire 23 to negative terminal 27 thus it is seen that this is equivalent to closing circuit 1, which in turn closes circuit 2 and 3,.but it must be borne in mind that we now have blades 42, 37 and f 35 of the limit switch closed with contactors 45, hence field coil 173 instead of field coil 40 will be included in circuit 3, and the latch motor will operate in the reverse direction, closing the latch ,which holds'the track switch firmly in position.

At the limit of travel. of the latch bolt 41, Fig. 2, the limit switch 36 is thrown again to. its original position, opening circuits 2 and 3 and stopping the motor- This movement of the limit switch turns ratchet wheel 48 in a counter clockwise directiomso insulation segment 47 will then occupy the position shown in the diagram for insulation segment 47. In doing this, finger 46 does not make electrical connection with ratchet wheel 48, hence the track switch 31 and 169, contact finger 167, conmotor control circuit is'not energized and both motors are disconnected from the lines, thereby completing the cycle of. operation required to unlock the track switch, swing it in one direction andlock" it again. \Vith the track switch; connectingtrack sections 1 and 2, car 11'. would then be-run onto section v2 and againstop so contact shoe 16 wouldmake connection with the insulated rail section 7 0 with controller at the off; position and brakes set the" motor man would swing; the trackswitch back to its original position, thus opening the main line track byagain closing push but- 7 sequence. 1

tonswitch 15, which, as has been shown, completes circuit 1, which in turn closes circuit 2 and 3 by means of the relay contacts 28 and 29. With these circuits once closed, the latch motor unlocks the track switch. The limit switch of this motor being thrown at end of travel of locking bolt, opening circuits 2 and 3 and momentarily closing circuit 1 by means of contact fingers 16 and ratchet 18. This closes contactors 60 and 61 which completes circuit 5, holding contactors 60 and 61 closed as before.

Because of the new position of thetrack motor limit switch we have anew control circuit, which we will designate as circuit 6 This circuit-is used to close contactors 138 and 139 by means of magnet coils 17 1 and 175, the flow of current .being from 63 through 68, 69, 164, 165 and 176 tothe point 177 where the circuit divides, the two branches uniting again at the point 178. The first branch is from 177 through contacts 179 and wire 180 and magnet .coil 175 to 178. The second branch is from' 177 through wire 181, contacts 182, wire 183, magnet coil 174 and wires 88 and'89 to 178. From 178 the circuit is through wires 90 and 91 to terminals 83. v a

With contactors 60, 61, 138 and139 closed, current can flow from positive terminal 30 through 60, 95, 121,107, 138, 111, 51, 110, 109, 139, 113, 11 1, 115, and 61Qtothe negative terminal 38. This completes the circuit hereinafter designated as circuit 7 and allows current to flow through armature 51 in the reverse direction to that in which it flows when circuit'7 is completed; hence the direction of the rotation of the motor is reversed and it moves the track switch in the reverse direction, thus closing the main line track, the motor being accelerated by the four branches of circuit 8.

At the limit of travel of the track switch, ,thetrack motor limit switch is thrown over to its original position, thus opening cir cuits 5, 6 7 8- and M-B and momentarily closing circuit 9, which closes circuits 2 and 3 operating the latch motor to run the latch bolt into place. At the end of travel of the latch bolts the operation of the limit switch 36 trips off circuits 2 and 3, leaving the apparatus in its original condition in every particular. 1 a I Circuit 1 comprises a momentary contact circuit which s'ervesto stantthe sequence of operations by energizing the relay solenoids 21 and 22, the operation being automatic from the tim'euntil the completion of the Circuit 2 is the relay holding circuit which keeps the relay contacts 28? and 29 closed alter circuitl hasbeen'broken. 7

;Circuit 3 is the latch motor circuit, including the field magnetwinding 40,.which unlocks the movable track section. At the limit of the latch bolt travel the limit switch 36 isthrown, opening circuit 2, and consequently circuit 3, which thenincludes field magnet winding 173 instead of 40, causes rotation in the reverse direction when circuit 3 is again closed andvice versa.

Circuit 1 is a momentary contact'circuit closedby the operation of the limit switch 36 at the end of the unlock interval. sl -This circuit is not closed, however, at the end of the lock interval of operation of the motor. The purpose of this circuit is to close contactors 60 and 61 by energizing magnet coil 54. I i

Circuit 5 holds contactors 60 and 61 closed after being first closed by circuit 4. This circuit includes coil 54 and the track motor limit switch which breaks the circuit by allowing contactors 60 and 61 to open. This is the main control circuit for the track motor. 7

i The following circuits,M-B, 6 6 7 7B and 8 are energized only when contactors 61 and 60 are closed. a

Circuit M-B includes. the brake magne coil 81, which releases the brake, thus allowing the track motor to operate freely,

Circuit 6 is closed whencontacts 60 and 61 are closed only for one positionofsthe track; motor limit switclt The position of the limit switch is determined by the previousj direction of rotation of the track motor,xtherefore, whenever circuit 6 is complete, closing conta'ctors86 and 7 8, the track motor will operate toswing the track section in a predetermined direction.

Circuit 6 issimilar inevery respect to circuit 6*. except that it closes contactors 138 and 139, thus operating the track motor in thereverse direction and returning the tracksection to its original position;

Circuit 7 is the main power circuit to drive the ,track motor which swings the track section from its original position. Control circuit 5 and 6 provide this motor and 7 8, a v 7 Circuit 7 8 is formed when control circuits 5 and 6 close contactors 60, 61, 138 and 139, thus completing the track motor circuit again, the current flow through the armature is reversed and the track section returned to its original position.

Circuit 8 is a track motor accelerating control circuit consisting of four branches, closing in order 1, 2, 3 and 4, which in turn close contactors 118, 119, 120 and 121 in the same order; The automatic closing of the severalibranches of this circuit is accomplished by means of the current limit relay coils 93, 101, 99a'nd 97, which control the movement of their respective plungers 122, 123, 121 and 125], closing in succession contacts 126, 127, 128 and 129.

Circuit 9 is closed momentarilyby (ion Cir tactsegments 166, making contact with contactor fingers 167 and 168 as th track motor limit switch is thrown from one position to another. The object of this circuit is to close circuits 2 and 3 by means of the relays 21 and 22, thus operating the latch motor so as to lock the track switch in position at.

either extremity of its travel. It will also be jit'ited that circuit'l serves to unlock the track switch in each case.

In order to prevent the closing of the contactors accidentally, or in the wrong order,

the system includes mechanical interlocks (not shown in diagram) between contactors 86 and 138, also between 78 and 139, making track section, comprising a motor, devices it-impossible even manually to close contactors 138 and 139 when 86 and78 are closed, nor can 86 and 78 be closed when'138 and 139 are closed. This eliminates an element of danger due to accidental closing of the wrong contactors.

In add'tion to these mechanical interlocks, it will be evident from a study of the dia gram that the top contacts 182, 84, 179 and 76 of the disk interlocks controlled mechanicallyby the contactors 86, 138, 78 and 139, respectively provide an electrical interlock arrangement through the control circuits as follows: 7

Contactors 86 and 78 can be closed electrically only when 138 and 139 are open and therefore contacts 84 and 7 6 closed, (by the adjustable insulated copperdisk 84 shown) likewise 138 and 139 can be closed only when contactors 86 and 78 are open, therefore contacts 182 and 17 9 closed. I

To insure complete closing of co-ntactors 86 and 78 or 138 and 139 in theirturn before the starting resistance, grid sections 103, 104,

105 and 106 are cut out by means of the control circuits sections of circuit 8, contacts 148 and 146 in series must both be closed before circuit 8 is complete in the first case, and contacts 184 and 185 are required 'to complete it in the second case. a

The object of the current limit interlocks, the operation of which has been described, is to insur automatic. acceleration of the la'rge'track motor in minimum length of time, keeping the starting current always withinthe overload limit for the motor under consideration.

In case of fiashovers, short circuits or overloads,the motor is protected by means of a current-limiting relay consisting of a series coil 26, plunger 186, carrying the insulated copper disk 187, normally closing contacts 117. The relative relation between coil 26 and plunger'186 is adjustable so the device may be set for various ultimate current strengths. When the current through coil 26 exceeds the'predetermined value, the attraction between the plunger and coil is great enough to raise the plunger and break circu t 5 which allows contactors 60 and 61 to open and break the main motor and. con tactor circuits connected between terminals 63 and 83. To start the operation of the track'motor again, it is necessary simply to manually close'contactors 60 and 61.

An inspection of Figs. 3 and 4 will make obvious the operation of this control'system when applied to the turntable or draw span.

It is obvious that changes in the precise arrangement of the various electrical devices herein described and shown may be resorted to within the scope of the following claims.

What we claim as new,'and desire to protectby Letters Patent, is z- 1. An electrical "control for a railroad connected therewith for locking and unlocking said track section, a switch to start said motor whereby it will unlock said track section, a limit switch to stop said motor, another motor adapted to move said track section after it is unlocked, means for accelerating the speed of said last named -motor and means adapted to start said first named motor in a reverse direction to lock said track section after it has been moved. y

2. The combination with a movable track section of locking means for said track section, a latch motor for actuating said locking means, means for moving said track section, a motor for actuating said track moving means, a-circuit connected with said la'tch motor, a closing circuit for said latch motor circuit, contact mechanism operable at a distance from said track section for said closing circuit, a limit switch for breaking said latch motor circuit after said latch motor has made a predetermined number of revolutions, a circuit for said track operating motor, said circuit being adapted to be closed by said latch motor limit switch, a track motor limit switch adapted to break said track motor circuit and close said latch motor circuit at the end of a predetermined number of revolutions of saidtrack motor to reverse'said latch'imotor and means for causing successive operations of said-track motor to be in reverse directions. V p i The combination with a movable track section having two operative positions, of means for locking said track section in either ofsaid two positions,"a latch motor for driving said locking means, means for moving said track section between said two operative positions, atrack operating motor forsaid-track moving means, and a series of electrical circuits, the first of which is adapted to be energized by manually closing a switch and the remainder of which are adapted to be successively closed automatically to energize said latch motor whereby itwill unlock said track section, thence tofenergize said track motor whereby; it w'ill move said track and thence to energize said latch motor whereby it will tary contact circuit and maintained in a closed condition by said relay holding circuit, a latch operating motor connected with said latch motor circuit and adapted to con trol the locking and unlocking of said track section, a limit switch connected with said latch motor to break the said latch motor circuit at the end of a predetermined number of revolutions of said latch motor, a track operating motor for moving said track section, a circuit connected therewith and adapted to be closed by said limit switch at the same time that said latch motor circuit is broken, a brake for said track operating motor, accelerating circuits for said track operating motor, a track motor limit switch for breaking the circuit to said track operating motor and a circuit connected with the said latch operating motor and adapted to be closed by said track motor limit switch to start said latch operating motor in a reverse direction and lock said track section after it has been swung from one position to another.

5. The combination witha movable track section of means for locking said track section in a fixed position, a latch operating motor for actuating said locking means, a track operating motor for moving said tracksection from one position to another, an electric circuit connected with said latch operating motor and adapted to be closed to actuate said latch operating motor and unlock said track section, a limit switch to break said latch operating motor circuit at the end of a predetermined period of action of said latch operating motor, an electric circuit connected with said track operating motor for energizing the same, said circuit being adapted to be closed by said latch op era-ting motor limit switch when said latch operating motor circuit is broken, a track motor limit switch adapted to break the circuit to said track motor after apredetermined number of revolutions of said track motor and another circuit connected with said latch operating motor and adapted to be closed by said track motor limit switch to rotate said latch operating motor in a reverse direction and lock said track section.

6. Thecombination with a movable track section, having two operative positions of means for locking said track section in either of said two positions, a lock motor for driving said locking means, a track motor adapted to swing said tracksection from one to the other of said positions, circuits for said latch motor, a limit switch for said latch motor circuits, circuits for said track motor, contactors in said track motor circuits, certain of said contactors being adapted to close said circuits and drive said motor in one direction and others'of said contactors being adapted to close said circuits and drive said track motor in a reverse direction and safety devices for preventing the closing of said contactors out of their proper order.

Signed by us at Seattle, \Vashington, this 29 day of 1918.

HEN RY- R. STEVENS. ROBERT L. ROCKWELL. ERNEST G. HOWE. Witnesses:

ROYAL A. MoCLURn, R. J. Coon. 

